Process for breaking petroleum emulsions employing certain oxyalkylated pentaerythritols



1958 M. DE GROOTE ETAL ,819,

PROCESS FOR BREAKING PETROLEUM EMULSIONS EMPLOYING CERTAIN OXYALKYLATEDPENTAERYTHRITQLS Filed May 24, 1954 BUTYLENE OXIDE I00 ,/6

PENTAERYTHRITOL I00 OXIDE 100 73 INVENTORS PROCESS FOR BREAKINGPETRQLEUM EMUL- SIONS EMPLOYENG CERTAEN OXYALKYLATED PENTAERYTHRITOLSMelvin De Groote, University City, and Owen H. Pettingill, Kirkwood, Mo,assignors to Petrolite Corporation, Wilmington, Del., a corporation ofDelaware Application May 24, 1954, Serial No. 431,787

26 Claims. (Cl. 252331) This invention relates to processes orprocedures particularly adapted for preventing, breaking or resolvingemulsions of the water-in-oil type, and particularly petroleumemulsions.

Our invention provides an economical and rapid process for resolvingpetroleum emulsions of the water-inoil type that are commonly referredto as cut oil, roily oil, emulsified oil, etc., and which comprise finedroplets of naturally-occurring waters or brines dispersed in a more orless permanent state throughout the oil which constitutes the continuousphase of the emulsion.

It also provides an economical and rapid process for separatingemulsions which have been prepared under controlled conditions frommineral oil, such as crude oil and relatively soft waters or weakbrines. Controlled emulsification and subsequent demulsification underthe conditions just mentioned are of significant value in removingimpurities particularly inorganic salts, from pipeline oil.

More specifically then, the present invention is concerned with aprocess for breaking petroleum emulsions employing a demulsifierincluding a cogeneric mixture of a homologous series of glycol ethers ofpentaerythritol. The cogeneric mixture is derived exclusively frompentaerythritol, ethylene oxide and butylene oxide in such Weightproportions so the average composition of said cogeneric mixture statedin terms of initial reactants lies approximately Within the S-sidedfigure of the accompanying drawing in which the minimum pentaerythritolcontent is at least 1.5% and which 5- sided figure is identified by thefact that its area lies within the straight lines connecting A, B, C, D,and H.

We have found that when pentaerythritol is combined with butylene oxideand ethylene oxide in certain proportions and particularly when thebutylene oxide is employed first, followed by use of ethylene oxide andmore especially if the butylene oxide employed is one of the straightchain isomers or a mixture of the two, and if the composition fallswithin the limits indicated by the 5-sided figure on the hereto attachedtriangular chart, said derivatives are of unusual efiectiveness for anumber of purposes particularly when surface activity is a factor,either directly or 2,8i922h Patented Jan. 7, 1958 ice indirectly. Oneexample is the use of such derivatives in the resolution of petroleumemulsions of the water-inoil type.

In a general way the compounds which have been found most effective andfall within the limits of the chart are combinations where one part ofpentaerythritol has been treated with about 11 to 39 parts of butyleneoxide, by weight, and then reacted with 27 to 58.5 parts of ethyleneoxide.

In another series 10 parts of pentaerythritol have been reacted with 5parts by weight of butylene oxide and 85 parts by weight of ethyleneoxide. -In another series 1.5 parts by weight of pentaerythritol havebeen reacted with 13.5 parts by weight of butylene oxide and 85 parts byweight of ethylene oxide. Similarly, in another series the following--combinations have been used: 1.5 parts of pentaerythritol combinedwith 58.5 parts by weight of butylene oxide and 40 parts by weight ofethylene oxide; 20 parts by weight of pentaerythritol, reacted with 40parts by weight of butylene oxide and then with 40 parts by weight ofethylene oxide. in another series 20 parts by Weight of pentaerythritolwere reacted with 10 parts by weight of butylene oxide and then parts byweight of ethylene oxide.

It is of interest to note in some instances as little as 1.5 parts ofpentaerythritol may be combined with 98.5 parts of the two oxides toproduce very valuable derivatives.

We have also found that where part of the butylene oxide is replaced bypropylene oxide, i. e., where a combination of pentaerythritol, butyleneoxide, propylene oxide and ethylene oxide are used, effective andvaluable surface-active agents can also be obtained. This, however,represents a separate invention.

For the purpose of resolving petroleum emulsions of the water-in-oiltype, we prefer to employ oxyalkylated derivatives, which are obtainedby the use of monoepoxides, in such manner that the derivatives soobtained have sutficient hydrophile character to meet at least the testset forth in U. S. Patent No. 2,499,368, dated March '7, 1950, to DeGroote and Keiser. in said patent such test for emulsificat-ion using awater-insoluble solvent, generally xylene, is described as an index ofsurface activity.

The above mentioned test, i. e., a conventional emulsification test,simply means that the preferred product for demulsification is solublein a solvent having hydropho-be properties or in an oxygenated waterinsoluble or even a fraction of a water-soluble hydrocarbon solvent andthat when shaken with water the product may remain in the nonaqueoussolvent or, for that matter it may pass into the aqueous solvent. Inother Words, although it is xylene soluble, for example, it may also bewater soluble to an equal or greater degree.

For the purpose of convenience what is said hereinafter will be dividedinto three parts:

Part 1 is concerned with the oxyalkylation of pentaerythritol ingeneral;

Part 2 is concerned with the oxyalkylation of pentaerythn'tol using twodilferent oxides, i. e., butylene oxide and ethylene oxide so as toproduce derivatives falling within certain composition limitationshereinafter noted in detail. For convenience, Part 2 is divided into twosections, Section A is concerned With oxybutylation and oxyethylationbroadly, and Section B is concerned with the particular compositionscorresponding to the herein specified compositions and illustrate suchcombinations;

Part 3 is concerned with the resolution of petroleum emulsions of thewater-in-oil type by means of the previously described chemicalcompounds.

PART 1 At the present time there is available butylene oxide whichincludes isomeric mixtures; for instance, one manufacturer haspreviously supplied a mixed butylene oxide which is in essence a mixtureof l-butene oXlde, 2-butene oxide isomers and approximately isobutyleneoxide. Another manufacturer has supplied an oxide which is roughly afifty-fifty mixture of the cisand trans-isomers of 2-butene oxide.

There is also available a butylene oxide which is characterized asstraight chain isomers being a mixture of the 1,2- and the 2,3-isomersand substantially free from the isobutylene oxide.

This latter product appears to consist of 80% of the 1,2 isomer and ofthe mixed 2,3 cisand 2,3 transisomer. We have obtained the best resultsby using an oxide that is roughly 80% or more of the 1,2 isomer and witheither none, or just a few percent if any, of the isobutylene oxide, thedifference being either form of the 2,3 or a mixture of the two forms.

Our preference is to use an oxide substantially free from theisobutylene oxide, or at least having minimum amounts of isobutyleneoxide present.

Since the varying solubility of different butanols is well known, it isunnecessary to comment on the effect that the varying structure has onsolubility of derivatives obtained by butylene oxide. Purely by way ofexample, the applicants have tested the solubility of the first twoavailable butylene oxides and noted in one instance the butylene oxidewould dissolve to the extent of 23 grams in 100 grams of water, whereasthe other butylene oxide would only dissolve to the extent of 6 grams in100 grams of water. These tests were made at 25 C.

As to further reference in regard to the isomeric butylene oxides areChemistry of Carbon Compounds, volume 1, part A, Aliphatic Compounds,edited by E. H. Rodd, Elsevier Publishing Company, New York, 1951, page671.

As to the difference in certain proportions of the cisand trans-form ofstraight chain isomers 2.3-epoxybutane see page 341 of A Manual ofOrganic Chemistry, volume 1, G. Malcolm Dyson, Longmans, Green andCompany, New York, 1950.

Reference to butylene oxide herein of course is to the compound orcompounds having the oxirane ring and thus excludes 1,4-butylene oxide(tetrahydrofurane) or a trimethylene ring compound.

When reference is made to the oxides, for instance, ethylene oxide andbutylene oxide, one can use the corresponding carbonates. Ethylenecarbonate is available commercially. Butylene carbonate, or thecarbonate corresponding to a particular oxide, is not availablecommercially but can be prepared by the usual methods in the laboratory.For this reason further reference to the alkylene carbonates will beignored although it is understood when oxyethylation takes place bymeans of ethylene carbonate one could of course, use butylene carbonatefor oxybutylation.

In the present invention we have found that outstanding products areobtained by the use of certain preferred butylene oxides, i. e., thoseentirely free or substantially free (usually 1% or less) and composed ofapproximately 85% or more of the 1,2 isomer with the remainder, if any,being the 2,3 isomer.

In the preparation of the outstanding compounds we have studiouslyavoided the presence of the isobutylene oxide as far as practical. Whenany significant amount of isobutylene oxide happens to be present, theresults are not as satisfactory regardless of the point when thebutylene oxide is introduced. One explanation may be the following. Theinitial oxybutylation which may be simplified by reference to amonohydric alcohol, produces a tertiary alcohol. Thus the oxybutylationin the presence of an alkaline catalyst may be shown thus:

Further oxyalkylation becomes diflicult when a tertiary alcohol isinvolved although the literature records successful oxyalkylation oftertiary alcohols. This does not necessarily apply when oxyalklationtakes place in the presence of an acidic catalyst, for instance, ametallic chloride such as ferric chloride, stannic chloride, aluminumchloride, etc.

The difficulty is that there may be some tendency on the part ofpentaerythritol to polymerize further, i. e., to form dipentacrythritolor the like. If this does happen to occur oxyalkylation would theninvolve pentaerythritol plus dipentaerythritol or even a higher polymer,and water in part. We have tried procedures such as using an alkalinecatalyst and pentaerythritol employing 4 to 6 moles of isobutylene oxideper mole of pentaerythritol. Afterwards an amount of acid was addedequal to the amount of caustic used as a catalyst and the reaction massdried and then stannic chloride added. Under such circumstances theresults suggest more satisfactory oxybutylation as such although theprocedure becomes cumbersome, uneconomical and perhaps even impractical.

This, however, seems to be only a partial explanation. Anotherexplanation may rest with the fact that isobutylene oxide may show atendency to revert back to isobutylene and oxygen and this oxygen maytend to oxidize the terminal hydroxyl radicals. This possibility ispurely a matter of speculation, but may account for the reason we obtainmuch better results using a butylene oxide as specified. In regard tothis reaction, i. e., possible conversion of an alkylene oxide back tothe olefine and nascent oxygen, see Tall Oil Studies: 11. Decolorizationof Polyethenoxy Tallates with Ozone and Hydrogen Peroxide, J. V.Karabinos et al., J. Am. Oil Chem Soc. 31, 71 (1954).

In order to illustrate why the herein contemplated compounds or saidproducts are cogeneric mixtures and not single chemical compounds, andwhy they must be described in terms of manufacture, and molal ratio orpercentage ratio of reactants reference is made to a mono hydricalcohol. Pentaerythritol, of course, is a polyhydric alcohol having 4hydroxyls. However, one need only consider what happens when amonohydric alcohol is subjected to oxyalkylation.

If one selects any hydroxylated compound and subjects such compound tooxyalkylation, such as oxyethylation, it becomes obvious that one isreally producing a polymer of the alkylene oxide except for the terminalgroup. This is particularly true where the amount of oxide added iscomparatively large, for instance, 10, 20, 30, 4G or 50 units. If such acompound is subjected to oxyethylau'on so as to introduce 30 units ofethylene oxide, it is well known that one does not obtain a singleconstituent which, for sake of convenience, may be indicated as RO(C HO) H. Instead, one obtains a cogeneric mixture of closely relatedhomologues in which the formula may be shown as the following: RO(C HO),,H, wherein n, as far as the statistical average goes, is 30, but theindividual members present in significant amount may vary from instanceswhere n has a value of 25 and perhaps less, to a point where n mayrepresent 35 or more.

Such mixture is, as stated, a cogeneric closely related series oftouching homologous compounds. Considerable investigation has been madein regard to the distribution curves for linear polymers. Attention isdirected to the article entitled Fundamental principles of condensationpolymerization, by Paul I. Flory, which appeared in Chemical Reviews,volume 39, No. 1, page 137.

Unfortunately, as has been pointed out by Flory and other investigators,there is no satisfactory method, based on either experimental ormathematical examination, of-

indicating the exact proportion of the various members of touchinghomologous series which appear in cogeneric condensation products of thekind described. This means that from the practical standpoint, i. e.,the ability to describe how to make the product under consideration andhow to repeat such production time after time with out difiiculty, it isnecessary to resort to some other method of description.

What has been said in regard to a monohydric compound of course ismultiplied many times in the case of a tetrahydric compound such aspentaerythritol. This is particularly true even in regard to ethyleneoxide alone but becomes even more complicated when butylene oxide isused in light of what has been said previously in regard to the isomersof butylene oxide.

PART 2 Section A We have found we can oxybutylate pentaerythn'tol or itspolymers for that matter in the same way that it is conventionallyoxypropylated. For example, we have followed directions which appear inU. S. Patents Nos. 2,626,907 and 2,626,908, both dated January 27, 1953,to De Groote, and also what appears in U. S. Patent No. 2,552,528, datedMarch 15, 1951, to De Groote. We have reacted pentaerythritol withbutylene oxide in the manner described in columns 16, 17, 18, 19 and 20in the aforementioned U. S. Patent 2,552,528 and particularly asdescribed in greater detail in regard to Examples 2, 22, 42 and 62 inTables I, II, III and IV of aforementioned U. S. Patent 2,552,528.Stirrer speed, temperature, time period, amount of solvent used, amountof catalyst used, and operating pressure were substantially the same.

Numerous other patents include specific information as to theoxypropylation of pentaerythritol and pentaerythritol polymers. Actuallythe procedure is substantially the same whether one uses butylene oxide,propylene oxide or ethylene oxide.

It is not believed any examples are necessary to illustrate such wellknown procedure but for purpose of illustration the following areincluded.

Example In The reaction vessel employed was a stainless steel autoclavewith the usual devices for heating, heat control, stirrer, inlet,outlet, etc., which is conventional in this type of apparatus. Thecapacity was approximately 4 liters. The stirrer operated at a Speed ofapproximately 250 R. P. M. There were charged into the autoclave 500grams of pentaerythritol, 300 grams of xylene, and grams of sodiummethylate. The autoclave was sealed, swept with nitrogen gas andstirring started immediately and heat applied. The temperature wasallowed to rise to approximately 145 C. At this particular time theaddition of butylene oxide was started. The butylene oxide employed wasa mixture of the straight chain isomer substantially free fromisobutylene oxide. It was added continuously at such speed that it wasabsorbed by the reaction as added. The amount added in this operationwas 1500 grams. The time required to add the butylene oxide was twohours. During this period the temperature was maintained at 128 C. to145 C., using cooling water through the inner coils when 6 necessary andotherwise applying heat if required. The maximum pressure during thereaction was 48 pounds per square inch. Ignoring the xylene and sodiummethyla-te and considering the pentaerythritol for convenience, theresultant product represents 3 parts by weight of butylene oxide to onepart by weight of pentaerythritol. The xylene present representedapproximately .6 of one part by weight.

Example 241 The reaction mass was transferred to a larger autoclave(capacity 15 liters). Without adding any more solvent or any more xylenethe procedure was repeated so as to add another 1500 grams of butyleneoxide under substantially the same operating conditions but requiringabout 3 hours for the addition. At the end of this step the ratiorepresented approximately 6 to 1 (ratio butylene oxide topentaerythritol).

Example 3a In a third step, instead of adding 1500 grams of butyleneoxide, 1625 grams were added. The reaction slowed up and requiredapproximately 5% hours, using the same operating temperatures andpressures. The ratio at the end of the third step was 9.25 parts byweight of butylene oxide per weight of pentaerythritol.

Example 4::

At the end of this step the autoclave was opened and an additional 5grams of sodium methylate added, the autoclave flushed out as before,and the fourth and final oxyalkylation completed, using 1625 grams ofbutylene oxide, and the oxyalkylation was complete within 3 hours usingthe same temperature range and pressure as previously. 'At the end ofthe reaction the product represented approximately 12.5 parts ofbutylene oxide by Weight to one part of pentaery-thritol.

All the examples, except the first step, were substantiallywater-insoluble and xylene-soluble.

As has been pointed out previously these oxybutylated pentaerythritolswere subjected to oxyethylation in the same manner described in respectto the oxypropylated pentaerythritol sucrose in aforementioned U. S.Patent No. 2,552,528. Indeed, the procedure is comparatively simple forthe reason that one is working with a liquid and also that ethyleneoxide is more reactive than butylene oxide. As a result, using the sameamount of catalyst one can oxyethylate more rapidly than usually at alower pressure. There is no substantial difference as far as operatingprocedure goes whether one is oxyethylating oxypropylatedpentaerythritol or oxybutylated pentaerythritol.

The same procedure using a slurry of finely powdered pentaerythritol inxylene was employed in connection with ethylene oxide and the samemixture on a percentage basis was obtained as in the above exampleswhere butylene oxide and pentaerythritol were used.

The same procedures have been employed using other butylene oxidesincluding mixtures having considerable isobutylene oxide and mixtures ofthe straight chain isomers with greater or lesser amounts of the 2,3isomer.

Where reference has been made in previous examples to the straight chainisomer, the product used was one which was roughly or more of the 1,2isomer and approximately 15% of the 2,3-cisand the 2,3-transisomer withsubstantially none or not over 1% of the isobutylene oxide.

In the preceding procedures one oxide has been added and then the other.One need not follow this procedure. The two oxides can be mixed togetherin suitable proportions and subsequently subjected to jointoxyalkylation so as to obtain products coming within the specifiedlimits. In such instances, of course, the oxyalkylation may be describedas random oxyalkylation insofar that one cannot determine the exactlocation of the butylene oxide or ethylene oxide groups. In suchinstances the procedure again is identically the same as previouslydescribed and, as a matter of fact, we have used such methods inconnection with molten sorbitol.

If desired, one may add part of one oxide and all of the other and thenreturn to the use of the first oxide, for instance; or one may use theprocedure as previously, adding first some butylene oxide, then ethyleneoxide and then the butylene oxide. Or, inversely, one may add someethylene oxide, then all butylene oxide and then the remainder of theethylene oxide; or either oxide could be added in portions so that firstone xide is added, then the other, then the first oxide is added again,and then the second oxide. We have found no advantage in so doing.Indeed, our preference has been to add all the butylene oxide first andthen the required amount of ethylene oxide.

As pointed out previously, pentaerythritol can be oxyethylated in thesame way it is oxybutylated, i. e., by preparing a slurry in xylene orin a similar solvent and using a suitable alkaline catalyst such ascaustic soda, sodium methylate, or the like, and then adding theethylene oxide. The changes previously mentioned are of difference indegree only. In other words, oxyethylation will take place at a lowertemperature, for instance, a top temperature of probably 130 to 135 C.instead of 145 to 150 C. The same weight of ethylene oxide could beadded in 75% to 85% of the time required for butylene oxide. Thepressure during the reaction, instead of being 35 to 45 pounds as in thecase of butylene oxide, is apt to be 10 to pounds and at times a littlehigher. Otherwise, there is no difference.

Also, if desired, the use of ethylene carbonate is a very convenient wayof oxyethylating pentaerythritol. In fact, it can be oxyethylatedwithout the use of pressure. Such procedure, and particularly meltingthe carbonate first and adding the powdered pentaerythritol slowlypermits the production of a reaction mass which is a liquid or whichmelts readily at comparatively low temperatures to yield a liquid. Suchreaction should be conducted in such a way that there is no residualethylene carbonate when the mass is transferred to an autoclave.

One can oxyalkylate using an acid catalyst or an alkaline catalyst or atleast in part, without the use of any catalyst although such procedureis extremely slow and uneconomical. In other words, any one of theconventional catalysts used in oxyalkylation may be employed. It is ourpreference, however, to use an alkaline catalyst such as sodiummethylate, caustic soda, or the like.

Actually, finely powdered pentaerythritol may contain a trace ofmoisture. Our preference is to prepare the slurry with an excess ofXylene and distill off one part of the xylene so as to remove any traceof water and then flush out the mass with nitrogen. Even so, there maybe a few tenths of a percent of moisture remain although at timesexamination indicates at the most it is merely a trace.

Section B In light of what has been said previously, particularly inSection A, it is obvious that hardly any directions are required toproduce the compounds herein specified. However, referring to thecomposition of the initial reactants based on the 5-sided figure in theattached drawing it will be noted we have calculated the percentage ofthe three initial reactants for the points A, B, C, D, E, F, G, H, I andI, which appear on the boundary of the 5- sided figure and alsodetermine the five subdivided parts of the 5-sided figure, two partsbeing triangles and the others being two parallelograms and onetrapezoid. Likewise, we have calculated the composition for a. number ofexamples within the area of the graph and corresponding to points 1 to18, inclusive. Note these data are included in Table I, immediatelyfollowing:

TABLE I Tertiary mixture, Binary intermediate mixtures,

percent basis percent basis Points on boundary of area Penta- Butyl-Ethyl- Pent-a Butyl- Penta- Ethylerythone one crythene erythone ritoloxide oxide ritol oxide ritol oxide 10. 0 5. 0 85. O 66. 6 33. 4 10. 589. 5 1. 5 13. 5 85. 0 10. 0 90. 0 1. 7 98. 3 1. 5 58. 5 40. 0 2. 5 97.5 3. 6 96. 4 20. 0 40. 0 40.0 33. 4 66. 6 33. 4 66. 6 1. 5 40.0 58. 5 3.6 96. 4 2. 5 97.5 1. 5 30.0 68. 5 4. 75 95.25 2. 14 97.86 1. 5 20.0 78.5 7.0 93. 0 1. 87 98.13 20.0 10.0 70.0 66.6 33. 4 22. 2 77.8 20.0 20.060.0 50.0 50.0 25.0 75.0 20.0 30.0 50.0 40. 0 60.0 28. 6 71. 4 5. 0 52.5 42. 5 8. 68 91.32 10. 5 89. 5 8. 0 44. 0 48.0 15. 4 84. 5 14. 3 85.7 1. 5 54. 5 44.0 2. 68 97. 32 3. 3 96. 7 18. 0 36. 5 45. 5 33. 0 67. 028. 3 71. 7 15. 0 33. 5 51. 5 31. 0 69. 0 22. 6 77. 4 7. 5 36. 5 56.017.1 82. 9 11.8 88. 2 1. 5 34. 5 64. 0 4.16 95.84 2. 3 97. 7 17.0 28.055.0 37. 7 62. 3 23. 6 76. 4 7. 0 26.0 07. 0 21. 2 78. 8 9. 5 90. 5 l3.5 22. 5 64. O 37. 5 62. 5 17.4 82.6 15. 5 19. 0 G5. 5 44. 8 55. 2 19. 280. 8

Note the first column gives the particular point on the boundary of theS-sided figure or within the 5-sided figure area. Note the next threecolumns represent the tertiary mixture which corresponds to the initialreactants, to wit, the percentages, by weight, of pentaerythritol,butylene oxide and ethylene oxide. Thus it is apparent that one couldselect any particular point and simply use the appropriate number ofpounds of oxide; for instance, in regard to point A all that would benecessary would be to mix 5 pounds of butylene oxide with '85 pounds ofethylene oxide and use the mixture to oxyalkylate 10 pounds ofpentaerythrito'l.

Similarly, in Example B, one need only mix 13.5 pounds of butylene oxidewith 85 pounds of ethylene oxide and use the mixture to oxyalkylate 1.5pounds of pentaerythritol in the manner previously indicated.

Note the fifth and sixth columns represent binary intermediate mixtures.For instance, in regard to the various points on the boundary and withinthe S-sided figure area, we have calculated the initial mixture usingpentaerythritol and butylene oxide in the first case, and usingpentaerythritol and ethylene oxide in the second case, which would beemployed for subsequent oxyalkylation to give the particular compositionrequired. Note that a binary intermediate for the preparation of point Acan be prepared in any suitable manner involving 66.6% ofpentaerythritol and 33.4% of butylene oxide. Thus, for example one coulduse 6'6.6 pounds of pentaerythritol and 33.4 pounds of butylene oxide,or on a larger scale one could use 666 pounds of pentaerythritol and 334pounds of butylene oxide.

Referring now to the tertiary mixture table, it is apparent that forpoint A pentaerythritol and butylene oxide together represent 15% andethylene oxide 85%. Therefore, one could employ 15 pounds of the binarymixture and react it with 85 pounds of ethylene oxide.

Similarly, in regard to the fifth and sixth columns for point -B, theinitial mixture involved pentaerythritol and butylene oxide,representing 10% of pentaerythritol and 90% of butylene oxide. Ifdesired, 10 pounds of penta erythritol could be reacted with 90 poundsof butylene oxide. Such mixture need only be reacted with ethylene oxideby reacting 15 pounds of the mixture with 85 pounds of ethylene oxide.This is obvious from the data in re gard to the tertiary mixtures.

Referring now to columns 7 and '8, it is obvious one could readilyproduce an oxyethylated pentaerythritol and then subject it to reactionwith butylene oxide. Using this procedure in regard to A, it is obviousthat the mixture represents 10.5% of pentaerythritol and 89.5% ofethylene oxide. This product could be obtained from a binary mixture of105 pounds of pentaerythritol and 895 pounds of ethylene oxide.

Referring now to the tertiary mixture table, it is obvious that 95pounds of such mixture could be reacted with pounds of butylene oxide togive point A. Similarly, in regard to point B the oxyethylatedpentaerythritol represents 1.7% of pentaerythritol and 98.3% ethyleneoxide. The mixture so obtained by referring to the tertiary mixturetable would be reacted with butylene oxide in the proportion of 86.5pounds of the mixture and 13.5 pounds of butylene oxide.

As previously pointed out, the oxyalkylation of pentaerythritol has beendescribed in the literature and is described also in detail above. Allone need do is employ such conventional oxyalkylation procedure toobtain products corresponding to the compositions as defined. Attentionis again directed to the fact that one need not add the entire amount ofeither oxide at one time but that a small portion of one could be addedand then another small portion of the other, and the process repeated.

Purely for purpose of illustration, we have prepared examples threediiferent ways corresponding to the compositions shown on the chart. Inthe first series the butylene oxides and ethylene oxide were mixed; thisseries is indicated as Aa, Ba, through and including 18a; in the secondseries butylene oxide was used first followed by ethylene oxide and thisseries indicated Ab, Eb, through and including 18b; and finally in thethird series ethylene oxide was used followed by butylene oxide and theseries identified as Ac, Bc, through and including 18c.

TABLE II Composition Composition Composition where butylwhere ethyl-Composition corresponding where oxides ene oxide is ene oxide is tofollowing point are mixed used first used first prior to oxyfollowed byfollowed by alkylation ethylene butylene oxide oxide The productsobtained by the above procedure usually show some color varying from alight amber to a pale straw. They can be bleached in the usual fashionusing bleaching clays, charcoal, or an organic bleach, such as peroxideor peracetic acid, or the like.

Such products also have present a small amount of kaline catalyst whichcan be removed by conventional means, or they can be neutralized byadding an equivalent amount of acid, such as hydrochloric acid. For manypurposes the slight amount of residual alkalinity is not objectionable.

There are certain variants which can be employed without detracting fromthe metes and bounds of the inention, but for all practical purposesthere is nothing to be gained by such variants and the result is merelyincreased cost. For instance, any one of the two oxides can be replacedto a minor percentage and usually to a very small degree, by oxide whichwould introduce substantially the same group along with a side chain,for instance, one could employ glycidyl methyl ether, glycidyl ethylether, glycidyl isopropyl ether, glycidyl butyl ether or the like.

In the hereto appended claims reference has been made to glycol ethersof pentaerythritol. Actually it well may be that the products should bereferred to as polyol ethers of pentaerythritol in order to emphasizethe fact that the final products of reaction have more than two hydroxylradicals. However, the products may be considered as hypotheticallyderived by reaction of pentaerythritol with the glycols, such asethylene glycol, butylene glycol, propylene glycol, or polyglycols. Forthis reason there seems to be a preference to use the terminology glycolethers of pentaerythritol.

PART 3 As to the use of conventional demulsifying agents, reference ismade to U. S. Patent No. 2,626,929, dated January 7, 1953, to De Groote,and particularly to Part 3. Everything that appears therein applies withequal force and effect to the instant process, noting only that wherereference is made to Example 13b in said text beginning in column 15 andending in column 18, reference should be made to Example 18b, hereindescribed.

Having thus described our invention, what we claim as new and desire tosecure by Letters Patent, is:

1. A process for breaking petroleum emulsions of the water-in-oil typecharacterized by subjecting the emulsion to a demulsifying agentincluding a cogeneric mixture of a homologous series of glycol ethers ofpentaerythritol; said cogeneric mixture being derived exclusively frompentaerythritol, ethylene oxide and butylene oxide in such weightproportions so the average composition of said cogeneric mixture, statedin terms of initial reactants, lies approximately within the 5-sidedfigure of the accompanying drawing in which the minimum pentaerythritolcontent is at least 1.5% and which S-sided figure is identified by thefact that its area lies within the straight lines connecting A, B, C, D,and H.

2. The process of claim 1 with the proviso that oxyalkylation takesplace in presence of an alkaline catalyst.

3. The process of claim 1 with the proviso that oxyalkylation takesplace in presence of an alkaline catalyst and that the butylene oxide beadded first.

4. The process of claim 1 with the proviso that oxyalkylation takesplace in presence of an alkaline catalyst and that the butylene oxide beadded first, and with the further proviso that the butylene oxide issubstantially free from isobutylene oxide.

5. The process of claim 1 with the proviso that oxyalkylation takesplace in presence of an alkaline catalyst and that the butylene oxide beadded first, and with the further proviso that the butylene oxideconsists or or more of the 1,2-isomer and approximately 15% or less ofthe 2,3-isomeric form, and is substantially free from isobutylene oxide.

6. The process of claim 5 with the proviso that the reactant compositionfalls within the triangular area defined by C, D, and E.

7. The process of claim 5 with the proviso that the reactant compositionfalls within the parallelogram D, E, F, and .T.

8. The process of claim 5 with the proviso that the reactant compositionfalls within the parallelogram J, F, G, and I.

9. The process of claim 5 with the proviso that the reactant compositionfalls within the trapezoid I, G, B, and H.

10. The process of claim 5 with the proviso that the reactantcomposition falls within the triangle H, B, A.

11. A process for breaking petroleum emulsions of the water-in-oil typecharacterized by subjecting the emulsion to a demulsifying agentincluding a cogeneric mixture of homologous series of glycol ethers ofpentaerythritol; said cogeneric mixture being derived exclusively frompentaerythritol, ethylene oxide and butylene xide in such weightproportions so the average composition of said cogeneric mixture, statedin terms of initial reactants, lies approximately within the -sidedfigure of the accompanying drawing in which the minimum pentaerythritolcontent is at least 1.5% and which 5-sided figure is identified by thefact that its area lies within the straight lines connecting A, B, C, D,and H; with the proviso that the hydrophile properties of said cogenericmixture in an equal weight of xylene are sufficient to produce anemulsion when said xylene solution is shaken vigorously with one tothree volumes of Water.

12. The process of claim 11 with the proviso that oxyalkylation takesplace in presence of an alkaline catalyst.

13. The process of claim 11 with the proviso that oxyalkylation takesplace in presence of an alkaline catalyst and that the butylene oxide beadded first.

14. The process of claim 11 with the proviso that oxyalkylation takesplace in presence of an alkaline cata lyst and that the butylene oxidebe added first, and with the further proviso that the butylene oxide issubstantially free from isobutylene oxide.

15. The process of claim 11 with the proviso that oxy- 1 2 alkylationtakes place in presence of an alkaline catalyst and that the butyleneoxide be added first, and with the further proviso that the butyleneoxide consists of or more of the 1,2-isomer and approximately 15% orless of the 2,3-isomeric form, and is substantially free fromisobutylene oxide.

16. The process of claim 15 with the proviso that the reactantcomposition falls within the triangular area defined by C, D, and E.

17. The process of claim 15 with the proviso that the reactantcomposition falls within the parallelogram D, E, F, and I.

18. The process of claim 15 with the proviso that the reactantcomposition falls within the parallelogram J, F, G, and I.

19. The process of claim 15 with the proviso that the reactantcomposition falls within the trapezoid I, G, B, and H.

20. The process of claim 15 with the proviso that the reactantcomposition falls within the triangle H, B, A.

References Cited in the file of this patent UNITED STATES PATENTS2,507,910 Keiser et al May 16, 1950 2,527,970 KGliQl Oct. 31, 19502,574,544 De Groote Nov. 13, 1951 2,617,830 Kosmin Nov. 11, 19522,624,766 Butler Ian. 6, 1953 2,662,859 Kirkpatrick Dec. 15, 19532,677,700 Jackson et al. May 4, 1954

1. A PROCESS FOR BREAKING PETROLEUM EMULSIONS OF THE WATER-IN-OIL TYPECHARACTERIZED BY SUBJECTING THE EMULSION TO A DEMULSIFYING AGENTINCLUDING A COGENERIC MIXTURE OF A HOMOLOGOUS SERIES OF GLYCOL ETHERS OFPENTAERYTHRITOL; SAID COGENERIC MIXTURE BEING DERIVED EXCLUSIVELY FROMPENTAERYTHRITOL ETHYLENE OXIDE AND BUTYLENE OXIDE IN SUCH WEIGHTPROPORTIONS SO THE AVERAGE COM-